The present invention relates to a liquid ejecting device, a head unit, and a liquid ejecting method.
A liquid ejecting device is a device that includes a liquid ejecting head (hereinafter referred to as “head”) that can eject various types of liquid. Examples of a typical liquid ejecting device include an image recording device such as a liquid-jet printing device (printer) that ejects a liquid ink onto a recording medium (placement target) such as recording paper from a nozzle provided to the head to record an image and the like.
It is important to design a liquid-jet printing device and the like so that a variation in ejection properties (e.g., a variation in the number of nozzles that simultaneously eject the ink, and a variation in the liquid travel speed and the liquid weight depending on the position of the nozzle) is reduced in order to improve the quality of the product. For example, JP-A-2010-188695 reduces a variation in ejection properties by driving the corresponding pressure-generating elements using a first drive waveform when the number of nozzles that simultaneously eject the ink is equal to or less than a predetermined threshold value, and driving the pressure-generating elements corresponding to the end nozzle group using the first drive waveform, and driving the pressure-generating elements corresponding to the center nozzle group using a second drive waveform when the number of nozzles that simultaneously eject the ink has exceeded the threshold value.
Even when a liquid droplet having an identical volume is ejected from the nozzle, residual vibrations after ejection may affect the subsequent ejection, and the placement timing may differ between the case where the first liquid droplet is ejected (first ejection) and the case where the second or subsequent liquid droplet is ejected (subsequent ejection). In particular, since it is difficult to provide an ejection interval that ensures that the residual vibrations stop when liquid droplets are ejected at high speed for implementing high-speed printing, the placement timing is significantly affected. When providing an additional drive signal having the drive waveform for the first ejection, it is necessary to additionally provide a drive signal generation section. This is not a practical solution since the circuit scale increases to a large extent.